This invention relates to a safety shield for a bolted-pressure contact switch and particularly to a safety shield which provides visual access to the switch contacts for determining the condition of the switch.
Fused load-break switches are frequently used as service entrance equipment and in other relatively high current applications. Typically, multiple-pole switches of this kind may be required to interrupt currents of 400 to 20,000 amperes. Most switches of this kind are provided with positive pressure-applying mechanisms for assuring good contact between the switch terminals. The contacts of these switches are opened and closed rapidly to minimize arcing and thereby avoid pitting and deterioration of the switch contacts. Rapid opening and closing of the switch contacts have been accomplished by the use of an overcenter spring drive. The spring drive can be energized and the switch actuated by manual or electrical means. The manual or electrical means is not used directly to open or close the switch contacts but, instead, operates a trip mechanism to release the spring drive. The use of electrical means such as electric motors or solenoids to actuate the switch and energize the spring drive permits remote operation of the switch but this, in turn, has increased the dangers to maintenance and repair personnel who are less likely to be aware of the actual condition of the switch contacts when they gain access to the switch housing. Opaque shields have been provided in front of the switch contacts to protect personnel against arcing but these prevent visual determination of the condition of the switch contacts.